On April 13, 1968 the Blairstown (NJ) Press reported on somehting encountered by zoologist and author Ivan T. Sanderson at his farm near Columbia, NJ (in Warren County). Sanderson and Walter McGraw heard a strange hooting cry. Both Sanderson and McGraw felt the sound was emanating from a large bird they saw flying along the Kittatinny Mountain. A similar cry came moments later from the opposite bank of the Delaware River. Mark A. Hall writing in Thunderbirds! The Living Legend of Giant Birds has called this creature the "Wooo-Wooo" after the mens' description of the sound and feels it is a representative of his hypothetical "Bighoot", a giant owl.
Pocono Ghosts, Legends and Lore by David J. Seibold and Charles J. Adams III reports on the presence in the Delaware Water Gap area (on the Pennsylvania side of the Delaware opposite Sanderson's home) of a creature called the "Hooter", which has been heard by hunters and hikers in the woods. It can be theorized that the second call Sanderson heard may have been the Hooter.